Medical waste incinerator

Abstract

A medical waste incinerator with primary and secondary incinerator chambers. The primary chamber has an "hour-glass" shape and air conduits that are directed downward to prevent clogging. There are no interior metal structures within the burning chambers. The primary incineration chamber uses sub-stoichiometric amounts of air.

What is claimed is: 
     
       1. A waste incinerator comprising: (a) a primary incinerator with a chamber therein defined by insulated walls having an approximate hourglass shape with a dilated upper portion having a top and a bottom, a dilated lower portion having a roof and a floor, and a constricting portion of said insulated walls forming a division between said upper portion and said lower portion with a central passage therein which communicated between said upper portion and said lower portion; wherein said constriction is further comprised of: (i) a top surface forming a downwardly sloping shelf constituting the bottom of said upper portion;   (ii) a upwardly sloping under surface forming the roof of said lower portion;     (b) means for feeding waste to be burned into said upper portion of said primary incinerator chamber;   (c) means for injecting and controlling a flow of fuel and air into said lower portion of said primary incinerator chamber and of igniting said fuel and air so as to burn said waste; wherein said means for injecting air comprises: (i) a plurality of generally downwardly directed air conduits in the walls and constricting portion of said lower portion of said primary incineration chamber through which air flow is directed in a generally downward direction toward the floor of said lower portion;     (d) a secondary incinerator located above said primary incinerator with a secondary incinerator chamber therein and with the upper portion of the primary incinerator chamber connected thereto by a stepped pipe which passes through said top of said upper portion of said primary incineration chamber and thence into said secondary incinerator chamber and through which gases and residue from said burned waste in said primary chamber may rise and flow therethrough into said secondary incineration chamber;   (e) means for injecting and controlling a flow of fuel and air into said secondary incineration chamber so as to further burn said gases and residue passing through said stepped pipe into said secondary incineration chamber; and   (f) means for venting the burned contents of said secondary incineration chamber to the exterior.   
     
     
       2. The waste incinerator of claim 1 wherein said flow of fuel and air into said lower portion of said primary incineration chamber has sub-stoichiometric amounts of air. 
     
     
       3. The waste incinerator of claim 1 wherein said flow of fuel and air into said secondary incineration chamber has at least stoichiometric amounts of air. 
     
     
       4. The waste incinerator of claim 1 wherein said chamber in said secondary incinerator contains at least one flow directing baffle therein. 
     
     
       5. The waste incinerator of claim 1 wherein air is injected by means contiguous to said stepped passageway in a direction parallel and co-directional with the flow of said gases from said primary incinerator chamber into said secondary incineration chamber. 
     
     
       6. The incinerator of claim 5 wherein said means to inject said air contiguous to said stepped passageway comprises an air manifold surrounding said passageway, a plurality of upwardly directed air injection nozzles in communication with said manifold, said nozzles oriented substantially upwardly and tangentially to said flow of gases. 
     
     
       7. A waste incinerator comprising: (a) a primary incinerator with a bifurcated chamber therein, in which said chamber has an upper portion, a lower portion and a constricting portion with a passage therethrough connecting said upper and lower portions;   (b) means for feeding waste to be burned into said upper portion of said primary incinerator;   (c) means for injecting fuel and air into said lower portion of said primary incinerator, and for igniting said mixture to burn said waste; wherein said air injecting means comprises: (i) a plurality of air conduits generally directed downwardly in the walls of said lower portion of said primary incinerator;   (ii) means for controlling said air flow to give sub-stoichiometric amounts of air;     (d) a secondary incinerator, having a chamber therein, and located upon said primary incinerator, and connected thereto by a stepped pipe which connects said chamber in said primary incinerator to said chamber in said secondary incinerator through which a flow of burn products and gases may pass from said primary incinerator chamber into said secondary incinerator chamber;   (e) at least one flow directing baffle in said chamber of said secondary incinerator;   (f) means for injecting fuel and air, in stoichiometric or greater amounts, into said chamber of said secondary incinerator, and of igniting same; and   (g) means for venting burn products from said secondary incinerator.   
     
     
       8. The waste incinerator of claim 7 wherein air is injected by means contiguous to said stepped passageway in a direction parallel and co-directional with the flow of said gases from said primary incinerator chamber into said secondary incineration chamber. 
     
     
       9. The incinerator of claim 8 wherein said means to inject said air contiguous to said stepped passageway comprises an air manifold surrounding said passageway, plurality of upwardly directed air injection nozzles in communication with said manifold, said nozzles oriented substantially upwardly and tangentially to said flow of gases. 
     
     
       10. A waste incinerator comprising: (a) a primary incinerator chamber divided into two connected portions: an upper portion and a lower portion, by a constricting division of the walls of said chamber, and in which a central passage therein provides communication between said two portions;   (b) means for introducing waste to be burned into said upper portion of said primary incinerator;   (c) means for injecting fuel into said lower portion of said chamber;   (d) means for injecting air into said lower portion of said chamber to mix with said fuel and of igniting said mixture to provide combustion thereof to burn said waste, said means for injecting air is a plurality of conduits in the walls of said lower portion of said chamber which are directed generally downwardly toward the floor of said lower portion;   (e) means for exhausting burn products from said primary incinerator after burning; and   (f) means for further combusting said exhausted burn products from said primary incinerator.